Placement of single or multiple tooth replacement implants has become more common over the last ten years. Surgeons rely on a variety of techniques for both planning and executing the surgery to place these implants. A more contemporary surgical approach is to utilize so called “flapless” surgery, a more minimally-invasive approach to placing dental implants. In this approach, small holes are “punched” through the soft tissue covering the bone of the jaw. The soft tissue of the mouth is commonly referred to as the mucosa. Small holes are punched through the mucosa of the mouth over the area where a dental implant will be placed into bone. Because of the size of the small hole, it is difficult to visualize the bone structure underneath, and to gauge where viable bone may reside. Dentists implanting these implants are thus often left to guess about what lies underneath the soft tissue during these procedures.
Several options exist for giving the dentist some information for bone quality underneath the mucosa. First, many dentists routinely use projection radiographs (x-rays) in the form of panoramic radiographs, lateral cephalometric radiographs or tomographic radiographs for judging bone quality in a specific area. More recently computed tomography and so-called cone-beam computed tomography (or cone-beam volume tomography) has been used to better identify bone shape, quality and quantity in a very specific area.
More recently dentists have relied on physical anatomical models produced using Solid Freeform Fabrication (SFF) techniques (additive fabrication techniques such as stereolithography, fused deposition modeling, three-dimensional printing, selective laser sintering, etc) to evaluate the bone in a very hands-on and tactile way. These models, often referred to as medical models or biomodels, can be used to simulate surgery and plan exactly the position, angulation, depth, etc of the implant. These models are made of the bone and teeth structure, the so called “hard tissue” anatomy of the jaw.
Many of these physical models are now being used to plan dental implant placement and subsequently fabricate a drill-guide that fits onto the patient's bone structure and allows for precise alignment of the drill for placement of the implants. What these anatomical models lack, however, is a representation of the soft tissue of the mouth to allow for creation of a soft tissue borne drill guide that would fit onto the patient's mucosa and provide a guide for “flapless” dental implant surgery.
As such, there are a number of challenges and inefficiencies created in traditional physical models used to plan and/or simulate surgery. For example, the traditional models do not provide a model for the soft tissue. As a result, a great amount uncertainty remains in surgery planning and simulation.